IEC62368 Wireless charging foreign body temperature rise tester steel disk aluminum ring aluminum sheet

IEC62368 Wireless charging foreign body temperature rise tester steel disk aluminum ring aluminum sheet Basic requirements:
A wireless power transmitter used for near-field wireless power transmission may heat a metallic foreign body that may be placed near or on the transmitter. In order to avoid burning due to the high temperature of metal foreign bodies, the transmitter is tested in accordance with regulations. (in fact, temperature rise test) foreign body specification:
1. Steel sheet Figure 47;
2. Aluminum ring Figure 48;
3. Aluminum foil Figure 49
Test steps:
The wireless power transmitter is placed at room temperature
Each foreign body is tested by placing it directly on the transmitter. Each trial has four cycles:
Without a receiver, the foreign body directly touches the transmitter;
The receiver is in direct contact with a foreign body;
The receiver is placed 2mm away from the foreign body
The receiver is placed 5mm away from the foreign body
The transmitter operates at maximum transmitting power.
Note: The test was not intended to test the temperature of the receiver, so any compatible receiver capable of extracting maximum power from a wireless power transmitter can be used, and the temperature of the receiver does not need to be monitored.
During each cycle, the foreign body can be moved on the transmitter in order to find the position that can produce the highest temperature.
The temperature of the foreign body shall not exceed 70°C during the test